The Information Security Officer (ISO) believes that the company has been targeted by cybercriminals and it is
under a cyber attack. Internal services that are normally available to the public via the Internet are inaccessible,
and employees in the office are unable to browse the Internet. The senior security engineer starts by reviewing
the bandwidth at the border router, and notices that the incoming bandwidth on the router’s external interface ismaxed out. The security engineer then inspects the following piece of log to try and determine the reason for
the downtime, focusing on the company’s external router’s IP which is 128.20.176.19:
11:16:22.110343 IP 90.237.31.27.19 > 128.20.176.19.19: UDP, length 1400
11:16:22.110351 IP 23.27.112.200.19 > 128.20.176.19.19: UDP, length 1400
11:16:22.110358 IP 192.200.132.213.19 > 128.20.176.19.19: UDP, length 1400
11:16:22.110402 IP 70.192.2.55.19 > 128.20.176.19.19: UDP, length 1400
11:16:22.110406 IP 112.201.7.39.19 > 128.20.176.19.19: UDP, length 1400 Which of the following describes
the findings the senior security engineer should report to the ISO and the BEST solution for service restoration?

A.
After the senior engineer used a network analyzer to identify an active Fraggle attack, the company’s ISP
should be contacted and instructed to block the malicious packets.

B.
After the senior engineer used the above IPS logs to detect the ongoing DDOS attack, an IPS filter should
be enabled to block the attack and restore communication.

C.
After the senior engineer used a mirror port to capture the ongoing amplification attack, a BGP sinkhole
should be configured to drop traffic at the source networks.

D.
After the senior engineer used a packet capture to identify an active Smurf attack, an ACL should be placed
on the company’s external router to block incoming UDP port 19 traffic.